Turbodrill



M. MITCHELL TURBODRILL 3 Sheets-Sheet 1 Filed June 10, 1958 IN VENTOR.

M lTCH E LL Q 7 a m E \V w I E2 0 8 E 5 m 9 5 R D 2 2 H 2 9 l 9 l (T t i ii k MICHAEL M.. MITCHELL May 16, 1961 TURBODRILL 3 Sheets-Sheet 2 Filed June 10, 1958 I Ki NI RI INVENTOR.

MICHAEL MITCH ELL and.

14 TTORNFVE M. MITCHELL May 16, 1961 TURBODRILL 3 Sheets-Sheet 3 Filed June 10, 1958 INVENTOR.

MICHAEL MITCHELL United States Patent TURBODRILL Michael Mitchell, 2190 Queens Ave., West Vancouver, British Columbia, Canada Filed June 10, 1958, Ser. No. 741,119

11 Claims. (Cl. 121-80) This invention relates to improvements in drilling equipment known as turbodrills.

Turbodrills are usually used for drilling very deep holes in medium and hard rock formations when exploring and drilling for oil wells. Conventional rotary drill equipment is used for this purpose, but it is advantageous to use turbodrills when drilling in rock below 6000 to 7000 feet.

The conventional rotary drill rapidly loses much of its power as the bit moves downwardly due to friction of the rotating pipe in the hole. This rep-resents a great waste of power, and at 10,000 feet, it has inadequate power and speed at the bit for optimum drilling conditions. On the other hand, the turbodrill has all of its power available at the bit regardless of the hole depth.

The turbodrill has a motor connected directly to a rock bit and so designed that it moves downwardly in the hole immediately behind its bit. Water or mud is pumped down a tube that is connected to the motor to cause the latter to operate to rotate the bit at a desired speed. This water or mud flows out of the lower end of the motor into the bottom of the hole and washes the cuttings up to the top of the hole outside of the tube.

The main purpose of this invention is to provide a turbo motor for a drill that utilizes a higher percentage of the power avaliable from the fluid pumped down the tube extending to the motor. This motor is also simpler in construction and more easily manufactured than the prior motors in this field, and it includes improved sealing means for mounting it in a shell which is connected to the lower end of the drill tube. Conventional bits and thrust and radial bearings therefor are used.

The power unit fora turbodrill according to the present invention comprises a cylindrical casing, a plurality of elongated pockets extending longitudinally of the casing and opening inwardly thereof, a cylindrical rotor rotatably mounted in the casing extending the length of the pockets therein, an inlet and an outlet at opposite ends of the rotor, said outlet end of the rotor being adapted to be connected to a drill bit, elongated inlet and outlet chambers in and extending longitudinally of the rotor communicating respectively with the inlet and outlet thereof, means in the rotor separating the chambers, and means extending the length of each of the inlet and outlet chambers bringing said chambers alternately into communication with each pocket during rotation of the rotor, whereby fluid under pressure entering the inlet chamber through the rotor inlet is directed into the casing pockets, said fluid being exhausted from the pockets by the communicating means and through the outlet chamber and the rotor outlet.

This turbodrill power unit is mounted in a cylindircal shell which is connected to the lower end of the drill tube, said tube being in communication with the inlet end of the rotor. Any desired standard bit is connected to the outlet end of the rotor by a tube, said tube extending through suitable thrust and radial bearings mounted in an extension of the cylindrical shell.

Examples of this invention are illustrated in the accompanying drawings, in which:

Figure 1 diagrammatically illustrates a drilled hole with this turbodrill therein,

Figure 2 is an enlarged vertical section through the turbodrill and taken on the line 2-2 of Figure 1,

Figures 3 to 7 are cross sectional views taken respectively on the lines 3-3, 44, 5-5, 6-6 and 7-7 of Figure 2,

Figure 8 is a longitudinal central section through the rotor alone,

Figure 9 is a sectional view similar to Figure 8 through the rotor taken at right angles to the section of the latter figure,

Figure 10 is a perspective view of the inlet and outlet chambers of the rotor, an outline of said rotor being shown in broken lines,

Figure 11 is a perspective view of the rotor unit with parts thereof broken away,

Figure 12 is a cross section similar to Figure 5 through an alternative form of rotor unit, and

Figure 13 is a fragmentary detail illustrating a spring arrangement of the unit of Figure 12.

Referring to Figure 1 of the drawings, 11) is a vertical hole in the ground that has been drilled by a turbodrill 11. This drill is connected to the lower end of a tube or pipe 12 which extends above the surface of the ground and is connected to suitable pumping equipment, not shown. The turbodrill includes a standard bit at its lower end which, in this example, is a rock bit 15. This bit is rotated around a Vertical axis to grind or chew away the bottom 16 of the hole.

A cylindrical shell 20 is removably connected to the lower end of pipe 12 in any suitable manner, such as by means of an adapter 22. The outside diameter of this shell is less than the cross sectional diameter of the hole cut by bit 15. 5

The power or motor unit 25 of turbodrill 11 removably fits inside shell 20, as clearly shown in Figures 2 to 6. The power unit is retained in the shell in any desired manner, such as by means of a connector .28 having an upper threaded section 29 that screws into the lower end of the shell, and a lower threaded section 30.

Power unit 25 includes a cylindrical casing 35 which slid'ably fits in shell 20 and is held therein by connector 28. The casing is prevented from rotation within the shell in any convenient way, such as by means of one or more keys 37, see Figures 2 and 7, fitting in corresponding slots in the shell, connector and casing.

Casing 35 has a plurality of elongated pockets extending longitudinally and opening inwardly thereof. These pockets may be formed in casing itself, but it is preferable to provide a plurality of substantially flat vanes 40 secured to the inner surface of housing 35 and extending longitudinally thereof. These vanes are spaced apart to form elongated pockets 41 extending longitudinally of the casing. Each vane is provided with a movable flap 43 at one edge and extending the length thereof, each flap being located beside a pocket 41, and extending inwardly from its vane at an angle to a diameter line of the casing passing through the edge of its vane, as illustrated by line 44 in Figures 4 and 5. Each flap is swingable outwardly relative to its vane, and for this purpose, it has been found preferable to form each vane of natural or synthetic rubber, and to form its flap integrally therewith. Actually, any other flexible or semi-flexible material that will stand up to constant flexing may be used.

A cylindrical rotor 46 is rotatably mounted in casing 35 centrally thereof and extends the length of pockets 41 and beyond the opposite ends thereof. This rotor is spaced inwardly from vanes 40, while the inner edges of flaps 43 press against the outer surface of the rotor. This forms a pocket extension 48 communicating with each pocket 41 between the flap adjacent said pocket and the flap of the next pocket in the direction of rotation of the rotor, which is indicated by arrow 49 in Figures 4 and 5. It will be noted that all the flaps extend in the direction of rotation of the rotor.

One or more lobes 50 are formed or mounted on the outer surface of rotor 46 and extend the length of pockets 41. There are two diametrically located lobes in the illustrated example of the invention. These lobes may be formed of any suitable material, but they are preferably formed of natural or synthetic rubber. Each lobe is bevelled along its leading edge 52 With reference to the direction of rotation of the rotor, and has a fiat trailing edge 52.

Suitable bearings and seals are provided at the ends of rotor 46. These bearings space the rotor from casing 35 and seal the ends of pockets 41 and their circumferential extensions 48. An upper bearing 53 consists of a thick annular pad 54 formed of suitable resilient material, such as natural or synthetic rubber, pressed between an outer ring 55 and an inner ring 56. The outer ring is threaded into the upper end of casing 35, and slidably fits around the adjacent end of rotor 46, while the inner ring abuts the upper ends of vanes 40 and their flaps. This inner ring may have seals 57 and 58 in its edges bearing against casing 35 and rotor 46. Ring 55 may be tightened or loosened to adjust the pressure of pad 54 on its lateral confining elements, casing 35 and rotor 46.

A lower bearing 59 is provided around rotor 46 spaced upwardly from the lower end thereof and bearing against the lower ends of vanes 40 and their flaps. This bearing is constructed in the same manner as bearing 53.

Rotor 46 has an inlet 61) at its upper end and an outlet 61 at its lower end. By referring to Figure 2, it will be seen that the rotor inlet is in communication with pipe 12 through adapter 22. Inlet and outlet chambers 63 and 64 are formed in the rotor communicating respectively with the inlet and outlet thereof. The main part of chamber 63 is located at the upper end of the rotor. The inlet chamber is separated from the outlet chamber by an insert or divider 66 positioned within the rotor and retained therein by rings 67 and 68. This insert is at least as long as pockets 41 surrounding the rotor and is opposite said pockets.

Insert or divider 66 is of odd shape that is best seen in perspective in Figure 10. The divider is formed with a central section 68 from which a pair of spaced diametrically opposite arms 69 and 70 project downwardly, and another pair of spaced diametrically opposite arms 72 and 73 project upwardly, the latter pair of arms being alternately arranged, relative to the former pair. Gutlet chamber 64 is located between arms 69 and 70, and the outer surfaces of said arms are hollowed out to form extensions 75 and 76 communicating with inlet chamber 63 located between arms 7-2 and 73. The outer surfaces of arms 69 and 79 are shaped to fit against the inner surface of rotor 46, and the lower ends of chamber extensions 75 and 76 are closed by the lower ends 78 and 79 of said arms.

Similarly, the outer surfaces of arms 72 and 73 are hollowed out to form extensions 81 and 82 communicating with outlet chamber 64. The outer surfaces of these arms are shaped to fit against the inner surface of rotor 46, and the upper ends of chamber extensions 81 and 82 are closed by arm ends 83 and 8 4.

With this arrangement, inlet chamber 63 is relatively large at the rotor inlet 60 and tapers inwardly to central section 68 of divider 66 and then is divided into two extensions 75 and 76 in arms 69 and 79, respectively. These chamber extensions preferably gradually diminish in cross sectional. area towards arm ends 78 and 79. Outlet chamber 64 is comparatively large at the rotor outlet 61 and tapers inwardly to the central section of the divider where it is divided into two diametrically opposed extensions 81 and 8-2 in arms 72 and 73 respectively. These extensions also get narrower in cross section towards their outer ends.

Means is provided throughout the length of each of the inlet and outlet chambers to bring said chambers alternately into communication with each pocket 41 during rotation of rotor 46. This may be done by means of slots or holes formed in the rotor. In this example, rows of holes or ports 87 and 88 are formed in the rotor op posite arms '72 and '73 and extend from the outer ends thereof to the opposite end of outlet chamber 64. Rows of holes or ports 90 and 91 are formed in the rotor opposite arms 69 and 70 and extend from the outer ends of said arms to the opposite end of intake chamber 63. By referring to Figures 4 to 6, it will be seen that outlet holes 87 and 8 8 are alternately arranged with inlet holes 90 and 91.

A tube 95 is connected at its upper end to the lower end of rotor 46 for rotation therewith by means of a suitable connector 96. The illustrated connector is threaded into the lower end of the rotor and is connected to the tube by splines illustrated at 97 in Figures 2 and 7. Bit 15 is removably connected to the lower end of tube 95 in any convenient manner. A cylindrical extension shell 99 is threaded on to the section 30 of connector 28 which secures it to shell 20. The shell extension surrounds and is spaced from tube 95 and terminates a little above bit 15. A plurality of radial and thrust bearings 101 are provided between the tube and shell exten- SlOIl.

During operation, the turbodrill 11 is fed into hole 10 in the usual manner. Fluid in the form of water, or what is commonly known in the industry as mud, is pumped down pipe 12 through inlet 60 of power unit 25. The fluid under pump pressure and its natural head flows into intake chamber 63 and radially through holes or ports 90 and 91 into pockets 41 and extensions 48. The reaction of this flow of the fluid causes rotor 46 to turn. At the same time, the pressure of the fluid in the pocket extensions 48 against the trailing edges 52 of lobes 50 in a circumferential direction applies power to the rotor. Looking at Figure 4, pressure in two of the pocket extensions is being applied to the two lobes 50. These lobes are moving past flaps 43 of four of the vanes, said flaps being swung outwardly by the lobes. The bevelled leading edges 51 of the lobes pry the flaps outwardly as said lobes approach the flaps. As each lobe clears a flap, the latter swings back to its normal position against the outer surface of the rotor to confine the fluid in the pocket extension ahead of said flap in the direction of rotation of the rotor. Thus, the flaps form swinging gates that permit the lobes to move past them, but prevent the fluid in the adjacent pockets and pocket extensions from moving in a direction reverse to that of the direction of rotation. The angular arrangement of the flaps relative to the radii of casing 35 prevents the flaps from swinging beyond their. proper positions in a direction counter to the protor rotation.

As the holes or ports 87 and 88 move past the pocket extensions, the fluid moves inwardly from said extensions. The reason for this is that the pocket extensions in effect get smaller as the lobes move through them towards the next vane flaps. The fluid passes through outlet chamber 64, rotor outlet 61 and pipe 95, whence it flows through and around bit 15 to wash cuttings upwardly through hole 10 around the turbodrill. The seals or bearings 53 and 59 rotatably support the rotor, and close the ends of the pockets and pocket extensions.

\Figures 12 and 13 illustrate an alternative form of vane, flap and lobe arrangement for the turbodrill. In place of casing 35, there is a cylindrical casing removably mounted in shell 20. This casing has a plurality ofspaced pockets 112 formed in and opening inwardlyof its inner surface and extending longitudinally thereof, said pockets being the same length as pockets 41. These pockets form vanes 114 therebetween on the inner surface of the easing, said vanes surrounding and being spaced from motor 46. The casing and vanes are formed of metal, and a flap 115 of the same or similar material is provided at the edge of each vane and the adjacent pocket 112. Each flap has a rounded rib 1 16 along an edge thereof fitting in a correspondingly-shaped recess 117 in the adjacent vane, and said flap is held in position by a plurality of springs 120, which also urge the inner edge of the flap against the outer surface of rotor 46. Each flap extends towards the rotor at an angle to the radius of the latter passing through the adjacent edge of its vane, as indicated by line 122.

Rotor 46 may have lobes 50 on its outer surface or, as shown, it may be provided with one or more lobes 125 that are similar in shape and purpose to the former lobes. Lobes 125 may be formed of metal or similar material.

The turbodrill of Figures 12 and 13 functions in the same manner as the one described above. Flaps 112 and lobes 125 operate in the same way as flaps 43 and lobes 50, Insert 66 separates the inlet and outlet or exhaust chambers as described above.

What I claim as my invention is:

1. In a turbodrill, a cylindrical casing, a plurality of elongated pockets extending longitudinally of the casing and opening inwardly thereof, a cylindrical rotor rotatably mounted in the casing extending the length of the pockets therein, circumferentially spaced lobes on the rotor outer surface extending longitudinally thereof and slidably bearing against the inner surface of the casing, swingable flap means on the inner surface of the casing at each pocket thereof, said flap means swinging to allow the lobes to pass during rotation of the rotor and preventing fluid from moving in a direction opposite to the direction of movement of the lobes, an inlet and an outlet at opposite ends of the rotor, said outlet end of the rotor being adapted to be connected to a drill bit, inlet and outlet chambers in the rotor communicating respectively with the inlet and outlet thereof, a divider in the rotor separating the inlet and outlet chambers; said divider comprising a central section located centrally of the rotor and having a plurality of hollow arms projecting therefrom towards the opposite ends of the rotor along and opening towards the inner surface of the latter, the interiors of the arms extending towards each end of the rotor communicating with the chamber at the opposite end thereof to form extensions for said chamber; and means extending the length of the inlet and outlet chambers and the extensions thereof bringing said chambers alternately into communication with each pocket during rotation of the rotor, whereby fluid under pressure entering the inlet chamber through the rotor inlet is directed into the casing pockets, said fluid being exhausted from the pockets by the communicating means and through the outlet chamber and the rotor outlet.

2. A turbodrill as claimed in claim 1 in which the side of each arm against the rotor is completely open, and the end of each arm remote from the central section of the fitting is closed.

3. In a turbodrill, a cylindrical casing, a cylindrical rotor rotatably mounted in and spaced from the casing, an inlet and an outlet at opposite ends of the rotor, said outlet end of the rotor being adapted to be connected to a drill bit, a plurality of spaced vanes on the inner surface of the casing extending longitudinally thereof and circumferentially arranged around the rotor, the spacing of the vanes forming elongated pockets therebetween, means closing the ends of the pockets, circumferentially spaced lobes on the rotor outer surface extending longitudinally thereof and slidably bearing against the inner surface of the vanes, swingable flap means on the inner surface of the casing at each pocket thereof, said flap means swinging to allow the lobes to pass during rotation of the rotor and preventing fluid from moving in a direction opposite to the direction of movement of the lobes, inlet and outlet chambers in the rotor communicating respectively with the inlet and outlet thereof, a divider in the rotor separating the inlet and outlet chambers; said divider comprising a central section located centrally of the rotor and having a plurality of hollow arms projecting therefrom towards the opposite ends of the rotor along and opening towards the inner surface of the latter, the interiors of the arms extending towards each end of the rotor communicating with the chamber at the opposite end thereof to form extensions for said chamber; and means extending the length of the inlet and outlet chambers and the extensions thereof bring-' ing said chambers alternately into communication with each pocket during rotation of the rotor, whereby fluid under pressure entering the inlet chamber through the rotor inlet is directed into the casing pockets, said fluid being exhausted from the pockets by the communicating means and through the outlet chamber and the rotor outlet.

4. In a turbodrill, a cylindrical casing, a cylindrical rotor rotatably mounted in and spaced from the casing, an in let and an outlet at opposite ends of the rotor, said outlet end of the rotor being adapted to be connected to a drill bit, a plurality of spaced vanes on the inner surface of the casing extending longitudinally thereof spaced outwardly from and circumferentially arranged around the rotor, the spacing of the vanes forming elongated pockets therebetween, means closing the ends of the pockets, a flap extending the length of an edge of each vane at a pocket swingable relative to said vane, said flaps being on the same edges of the vanes relative to the direction of rotation of the rotor, each flap normally extending inwardly and in said direction of rotation slidably to engage the rotor, at least one longitudinally-extending lobe on the outer surface of the rotor slidably fitting within the vanes, inlet and outlet chambers in the rotor communicating respectively with the inlet and outlet thereof, a divider in the rotor separating the inlet and outlet chambers; said divider comprising a central section located centrally of the rotor and having a plurality of hollow arms projecting therefrom towards the opposite ends of the rotor along and opening towards the inner surface of the latter, the interiors of the arms extending towards each end of the rotor communicating with the chamber at the opposite end thereof to form extensions for said chamber; and means extending the length of the inlet and outlet chambers and the extensions thereof bringing said chambers alternately into communication with each pocket during rotation of the rotor, whereby fluid under pressure entering the inlet chamber through the rotor inlet is directed into the casing pockets, said fluid being exhausted from the pockets by the communicating means and through the outlet chamber and the rotor outlet.

5. A turbodrill as claimed in claim 4 in which the lobes are bevelled along their leading edges with reference to the direction of rotation of the rotor and the trailing edges thereof are flat.

6. A turbodrill as claimed in claim 4 in which each flap is integrally connected to its vane and both are formed of rubber-like material.

7. A turbodrill as claimed in claim 6 in which each lobe is formed of rubber-like material.

8. A turbodrill as claimed in claim 4 in which each flap is hingedly connected to its vane, and including resilient means normally swinging said flaps against rotor.

9. In a turbodrill, a cylindrical casing, a cylindrical rotor rotatably mounted in and spaced from the casing, an inlet and an outlet at opposite ends of the rotor, said outlet end of the rotor being adapted to be connected to a drill bit, a plurality of spaced vanes formed of rubberlike material on the inner surface of the casing extending longitudinally thereof spaced outwardly from and circumferentially arranged around the rotor, the spacing of the vanes forming elongated pockets therebetween,

means closing the ends of the pockets, a flap formed of rubber-like material extending the length of an edge of each vane at a pocket integrally connected to said vane and swingable relative to the latter vane, said flaps being on the same edges of the vanes relative to the direction of rotation of the rotor, each flap normally extending inwardly and in said direction of rotation slidably to engage the rotor, at least one longitudinally-extending lobe on the outer surface of the rotor slidably fitting within the vanes, elongated inlet and outlet chambers in and extending longitudinally of the rotor communicating respectively with the inlet and outlet thereof, means in the rotor separating the chambers, and means extending the length of each of the inlet and outlet chambers bringing said chambers alternately into communication with each pocket during rotation of the rotor, whereby fluid under pressure entering the inlet chamber through the rotor inlet is directed into the casing pockets, said fluid being exhausted from the pockets by the communicating means and through the outlet chamber of the rotor outlet.

10. A turbodrill as claimed in claim 9 in which the lobes are formed of rubber-like material.

11. In a turbodrill, a cylindrical casing, a cylindrical rotor rotatably mounted in and spaced from the casing, an inlet and an outlet at opposite ends of the rotor, said outlet end of the rotor being adapted to be connected to a drill bit, a plurality of spaced vanes on the inner surface of the casing extending longitudinally thereof spaced outwardly from and circumferentially arranged around the rotor, the spacing of the vanes forming elongated pockets therebetween, means closing the ends of the pockets, a flap extending the length of an edge of each vane at a pocket swingable relative to said vane, said flaps being on the same edges of the vanes relative to the direction, of rotation of the rotor, each flap normally extending in-, wardly and in said direction of rotation slidably to engage the rotor, a pair of diametrically-opposed longitudinallyextending lobes on the outer surface of the rotor slidably fitting within the vanes, elongated inlet and outlet chambers in and extending longitudinally of the rotor communicating respectively with the inlet and outlet thereof, divider means in the rotor extending generally longitudinally thereof separating the inlet and outlet chambers and diminishing said chambers in cross sectional area away from said inlet and outlet respectively, and opening means in the rotor ahead of each lobe with reference to the direction of rotation of said rotor and extending the length of each of the inlet and outlet chambers bringing said chambers alternately into communication with each pocket during rotation of the rotor, whereby fluid under pressure entering the inlet chamber through the'rotor inlet is directed into the casing pockets, said fluid being ex hausted from the pockets by the opening means and through the outlet chamber and the rotor outlet.

References Cited in the file of this patent UNITED STATES PATENTS 28,282 Kennish May 15, 1860 550,919 Lesperance Dec. 3, 1895 860,549 Kleckner July 16, 1907 926,689 Coffield June 29, 1909 1,078,305 Ogle Nov. 11, 1913 2,749,843 Nubling June 12, 1956 FOREIGN PATENTS 8,185 Great Britain 1839 

